Scientists manage to remove nanoplastics from water with an efficiency greater than 98%

Scientists at the University of Missouri are battling an emerging enemy of human health: nanoplastics. Much smaller than the diameter of an average human hair, nanoplastics are invisible to the naked eye.

Linked to cardiovascular and respiratory diseases in humans, nanoplastics continue to accumulate, largely unnoticed, in the world’s water bodies. The challenge remains to find a cost-effective solution to get rid of nanoplastics while preserving drinking water.

That’s where Mizzou comes in. Recently, researchers at the university created a new liquid solution that removes more than 98 percent of these microscopic plastic particles from water.

An article describing this work is published in the journal ACS Applied Engineering Materials.

“Nanoplastics can disrupt aquatic ecosystems and enter the food chain, posing a risk to wildlife and humans,” said Piyuni Ishtaweera, a recent graduate who led the study while earning her doctorate in nanomaterials chemistry at Mizzou. “Simply put, we’re developing better methods to remove contaminants like nanoplastics from water.”

This innovative method, which uses water-repellent solvents made from natural ingredients, not only offers a practical solution to the pressing problem of nanoplastic pollution, but also paves the way for further research and development in advanced water purification technologies.

“Our strategy is to use a small amount of designer solvent to absorb plastic particles from a large volume of water,” said Gary Baker, associate professor in Mizzou’s Department of Chemistry and corresponding author of the study. “Currently, the capacity of these solvents is not well understood. As part of our future work, we want to determine the maximum capacity of the solvent. Additionally, we will investigate methods for recycling the solvents, allowing them to be reused multiple times if necessary.”

Initially, the solvent settles on the surface of the water, much like oil floats on water. Once mixed with the water and allowed to separate, the solvent rises to the surface, carrying the nanoplastics with it in its molecular structure.

In the lab, researchers simply use a pipette to remove the nanoplastic-laden solvent, leaving behind clean, plastic-free water. Baker said future studies will aim to scale up the entire process so it can be applied to larger bodies of water like lakes and, eventually, oceans.

Ishtaweera, who now works at the U.S. Food and Drug Administration in St. Louis, noted that the new method is effective in both fresh and salt water.

“These solvents are made from safe, non-toxic components, and their water-repellent properties prevent further contamination of water sources, making them a highly sustainable solution,” she said. “From a scientific perspective, creating effective removal methods drives innovation in filtration technologies, provides insights into the behavior of nanomaterials, and supports informed environmental policymaking.”

The Mizzou team tested five different sizes of nanoplastics made from polystyrene, a type of plastic commonly used in the manufacture of polystyrene cups. Their results surpassed those of previous studies that focused primarily on a single size of plastic particle.

Additional co-authors of the research are Collen Ray, Wyland Filley and Garrett Cobb.